1. About:-
Torch, Cell, Switch, Bulb, Torch Bulb,
2. How to light a bulb using a cell?
3. Electric Circuit
4. Electric Current
5. Brake Circuit
6. Fused Bulb
7. why do electric cell and the bulb have two terminals?
13. Electric Circuit
•Two terminals of the
electric cell are
connected to two
terminals of the bulb.
Such an arrangement
is an example of
Electric Circuit
14. Electric Current
•The bulb glows
only when current
flows through the
circuit.
•Current flows from
positive terminal to
negative terminal.
17. why do electric cell and the bulb have two
terminals?
Cell Bulb
Editor's Notes
Hello students, welcome to the second part of Electricity and Circuits
Today I am going to tell you about torch and functionality of its part
We have covered cell or battery in part-1 ,
now we will see other part that is bulb
So, A Torch has a bulb that lights up when it is switched on.
If you look inside the torch bulb, there is a thin wire fixed in the middle of the glass bulb,
So if you switch on the torch, you will see this part of the bulb is glowing.
The thin wire that gives off light is called the filament of the bulb
The filament is fixed to two thicker wires, which also provide support to it.
One of these thick wires is connected to the metal case at the base of the bulb.
The other thick wire is connected to the metal tip at the centre of the base.
The metal case of the bulb and the metal tip of the
base are the two terminals of the bulb.
Now the question is, How to light a bulb using a cell?
So to get answer we will do an activity, first take a torch bulb,
Here you can see these two terminals are fixed in such a way that they do not touch each other
So lets take a cell and join its positive terminal to metal case of bulb, we see that bulb does not glow.
it means, if we connect one terminal of cell to one terminal of bulb, bulb will not glow.
But as if we connect also negative terminal of cell to metal tip of a bulb, the bulb begin to glow, it means if connect both terminals of a cell to both terminal to bulb, bulb will glow, here we have done one thing that we connected positive terminal of cell to metal case and negative terminal of cell to metal tip of bulb. Now , lets change the joining way of terminal and check whether the bulb will glow or not
now we connect positive terminal of cell to metal tip instead of metal case and negative terminal of cell to metal case instead of metal tip of bulb, and now surprising thing is that bulb is still glowing, it means bulb does not have negative and positive terminal like cell
Now what is electric circuit, so when Two terminals of the electric cell are connected to two terminals of the bulb. Such an arrangement is an example of Electric Circuit
And next question is what about Electric Current
The bulb glows only when current flows through the circuit.
And Current flows from positive terminal to negative terminal
But if we brake the circuit Electric Current will not flow
And the example for this is fused bulb, in case of fused bulb, filament breaks down and because of that circuit does not allow to the flow current. And bulb does not glow.
So in this part we have covered bulb of torch, electric circuit and electric current and in the next part we will study about switch and how switch works
Now give me answer in comment box why do electric cell and the bulb have two terminals?
If you don’t know the answer watch the next video
Thanks for watching this video stay home stay safe
